SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e0b8b49a4a6681ccdffdbbc36e0004829a53d9d0b298224af611914eafdf9da' 
  AND token = 'DPKtDHI2d4zfgwpWeu746Wotv4KGs3PY2g/jfr75r1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}